1. Field of Invention
The invention relates to a novel water, energy, and time efficient reactive rapid dyeing process for the dyeing of cellulosic containing textile materials with fiber reactive dyestuffs whereby from scour through after-scour a total process time of less than 5 hours are employed and only from 5 to 6 liquor baths are required.
2. Description of Prior Art
Numerous processes have heretofore been utilized for the dyeing of textile materials such as fibers, yarns and fabrics with wide divergence among the process parameters, depending upon the particular material being dyed, and the particular type of dyestuff being employed. Of particular importance are processes that have been utilized to dye cellulosic textile materials with fiber reactive dyes.
In utilizing the conventional fiber reactive dyeing process, not only is the dyeing operation expensive and time consuming, but the process is particularly energy intensive. With different baths, sometimes as many as 12 or 14, substantial energy is expended for raising the bath temperature from ambient to elevated temperature conditions at several intervals during the process. Moreover considerable rework is necessary due to shade variability and unlevel dyeings due to strike rate and hydrolysis of reactive dyes and unnecessary dyestuffs and chemicals are therefore wasted in larger amounts; and the protracted length of time required to complete the dyeing reduces the production capacity of the dyeing equipment.
Presently, the availability of energy adequate to run energy intensive dyeing operations is of major concern, not to mention the tremendous cost of same. Consequently much effort has been devoted to improving dyeing processes, attempting to reduce energy requirements necessary for the dyeing of all materials, particularly cotton and viscose rayon with fiber reactive dyes which are notoriously expensive and time consuming using state of art techniques.
Heretofore, many different processes have been proposed for the dyeing of cellulose containing materials with fiber reactive dyes, although most of the work has been done on the dyeing part of the process, not much work has been done on the approach of involving the scouring, the dyeing, and the after-scouring as a one process per se. For example,
U.S. Pat. No. 5,356,444 to Schwarz, Max; Wolff, Joachim; Hildebrand, Dietrich; Grutze, Joachim; Hoppe, Manfred; Stawitz, Josef-Walter; Schulz, Rolf (Oct. 18, 1994)
Bayer Aktiengesellschaft recommends the following conventional fiber reactive dyeing and after-scouring procedure from the Prior Art U.S. Pat. No. 5,356,444:
100 parts of bleached cotton knitted goods and 3 parts of a phthalocyanine reactive dyestuff mixture are added to 1000 parts of aqueous dye liquor on a winch vat at 60 degrees C.
After the dyestuff mixture has become uniformly distributed in the liquor and on the cotton over a period of 15 minutes, 50 parts of sodium chloride are introduced into the dye liquor over a period of 30 minutes and 10 parts of sodium carbonate are then added at intervals of 10 minutes as 3 portions respectively comprising 1 part, 2 parts and 7 parts. The batch is then heated to 80 degrees C. in the course of 30 minutes and the goods are treated at this temperature for 30 minutes. After cooling, the liquor is then drained off and the goods are rinsed twice at 60 degrees C. and twice at 80 degrees C. They are then extracted at the boil for 15 minutes and the wash liquor is dried off. After cold rinsing, a level turquoise dyeing with good fastness properties is obtained.
It can be seen from the above-mentioned example that the electrolyte is dosed in a time period of 30 minutes, and that the alkali is also dosed in a time period of 30 minutes. In addition, six baths are used for the after-scouring with a combined temperature raise of 255.degree. C.
U.S. Pat. No. 4,359,322 to Neal, Bobby L.; Lowman,Steven R. (Nov. 16, 1982)
On the pre-scour operation of the goods, according to Neal in the Prior Art on U.S. Pat. No. 4,359,322, the goods are taken to 212.degree. F. (100.degree. C.), and run 30 to 45 minutes at said temperature, several rinses and an acid sour at 1 20.degree. F. (50.degree. C.), that is to say a total of 5 baths just for the pre-scour operation.
U.S. Pat. No. 5,364,416 to Schwarz, Max; Grutze, Joachim; Hildebrand, Dietrich; Wolff, Joachim; Stohr, Frank-Michael (Nov. 15, 1994)
Conventional after-scouring procedures are time consuming, energy intensive and of very high water consumption and effluents, as can be observed from the Prior Art U.S. Pat. No. 5,364,416 where after the dyeing procedure 2 warm water rinses at 50.degree. C., 2 hot water rinses at 80.degree. C., soaping at the boil for 15 to 20 minutes with suitable detergent, and cold water rinses until water is clear are performed in order to achieve good wash-fastness properties from a 2% fiber reactive dyed material, that is a total of seven water baths just for the after-scouring operation, plus a combined temperature rise of 235.degree. C.
U.S. Pat. No. 5,554,199 to Baumann; Hans-Peter (Sep. 10, 1996)
It is of common practice to add the alkali fixing dyestuff agent in several parts and at 5 to 10 minutes intervals during dyeing, as stated by Baumann in the Prior Art U.S. Pat. No. 5,554,199, where as stated in Application Examples A and B, after waiting a 30 minute period for the dyestuff exhaustion to take place, 5 additions of alkali at 5 minute intervals are made; the problem with this procedure being that its very hard to achieve perfect lot-to-lot color repetition, different strike rates causing shade variability and increasing undesirable reworks plus the fact that its time consuming.
U.S. Pat. No. 5,833,720 to Kent, Johnny Joe; Lee, Eric C. S.; Yu, Sui-Fung (Nov. 10, 1998)
Just on the preparation of the fabrics, according to Kent et al. in Prior Art U.S. Pat. No. 5,833,720, four full water baths are used, and while the temperature was set to 70.degree. C. and was held for 30 minutes, its well known to all skilled in the art that a much more efficient preparation of cotton materials take place at the boil.
In addition, according to the Prior Art U.S. Pat. No. 5,833,720, the energy efficient dyeing process works only with bifunctional reactive dyes, which is a big limitation to their dyeing process, since all the other type of fiber reactive dyestuffs will not work with their process.
U.S. Pat. No. 5,330,541 to Hall, David M.; Leonard, Tony M.; Cofield, Charles D.; Barrow, Hugh W. (Jul. 19, 1994)
As for the Dyeing time according to Hall et al. in the Prior Art U.S. Pat. No. 5,330,541 the average dyeing time of fiber reactive dyes is between 3 to 6 hours, and that with his process he can reduce the dyeing time from about 21/2 to about 3 hours, and to this time you have to add the preparation of the material time plus the conditioning of the material time which add up to an additional 31/2 to 4 hours, which at best will be 6 hours. Another disadvantage of the process of the Prior Art U.S. Pat No. 5,330,541 is that 5 water baths are required just for the preparation and conditioning of the cellulosic materials.
U.S. Pat. No. 4,562,604 to Damm, Sture (Jan. 7, 1986)
According to Damm, in the Prior Art U.S. Pat. No. 4,562,204, "if one used dyeing agents and optimum dyeing temperature of the dye bath, containing dyeing agent and electrolyte, adds all necessary alkali initially, one obtains with a great likelihood an uneven dyeing, as the fixation to the fibres is initiated at a high speed and reaches after a few minutes high values. On the other hand one can not reduce the amount of alkali, as it is necessary for attaining the end fixation value at a certain given dyeing time and consequently necessary for the reproducibility of the dyeing. The alkali is added after that the recommended dyeing temperature has been reached. As one can expect a not desired fast start of the fixation, the required amount of alkali must in usual manner be added in portions and at time intervals. These facts are known in several publications, for example in [Le Mustercarte 1350] from Bayer AG".
Which prove to be true for conventional fiber reactive dyeing processes, but at the same time these procedures are long and time consuming, and to this we have to add the disadvantage of having to spend money on expensive and sophisticated alkali dosing equipment devices like the one that Damm proposes in the Prior Art above mentioned,
U.S. Pat. No. 4,656,846 to Damm, Sture (Apr. 14, 1987) and also on his device proposed in the Prior Art U.S. Pat. No. 4,656,846, where the alkali is dosed in portions by means of an expensive sophisticated electronically programmed controlled dosing device.
U.S. Pat. No. 5,152,802 to Berger, Faize; Becker, Klaus; Hartschen, Christa; Wahle, Bernd; Schenker, Gilbert; Baehr, Bemd-Dieter (Oct. 6, 1992)
According to Berger et al. in the Prior Art U.S. Pat. No. 5,152,802, dyeing with fiber reactive dyes is performed simultaneously with a 4 component anionic and non-ionic surfactant composition without a pre-scouring operation, thus saving time in the process, but unfortunately good level dyeings are difficult to obtain even if the dyestuff formulation comprises just one dye, as can be seen in example 2, table 2 in the Prior Art U.S. Pat. No. 5,152,802 where dyeing levelness is assessed by them a 2-3 rating (1=very good, 6=very bad) on a 2% Levafix Brilliant Blue E-BRA dyeing, leaving one to wonder what kind of ratings could be obtained with 2 and 3 dyestuff formulae combinations. Besides, Berger et al. make no mention whatsoever as for the dyeing time employed in the dyeing process of their invention.
U.S. Pat. No. 4,976,743 to Ohba, Noriaki; Tabata, Yujin; Nagatsuka, Masaaki; Nagatomi, Tateyuki; Klicker, Helmut (Dec. 11, 1990)
In the Prior Art U.S. Pat. No. 4,976,743 (Ohba et al.) describes a leveling agent composition for the treatment of cellulosic fibers that results in improved dyeability with reactive dyes without the need of dosing of alkali or electrolyte, but no mention is made about complete process time, preparation or pre-scouring and after-scouring mode or time, nor amount of water used throughout the entire process, although the 18 comparative examples demonstrated by Orba et al. were runned using a very high 20:1 liquor to fabric ratio.
U.S. Pat. No. 5,015,262 to Ohba, Noriaki; Tabata, Yujin; Nagatomi, Tateyuki (14/0511991)
In the Prior Art U.S. Pat. No. 5,015,262, again Ohba et al. propose a dye leveling agent, based on phospholipid type-compounds, whereby no dosing of alkali is needed, making the process shorter, thus saving time, but according to their invention, hot reactive dyes can not be dyed by their procedure, since the dyeing curves they propose are performed either isothermally at 50.degree. C. as shown in FIG. 1, or at 60.degree. C. as shown on FIG. 2, which is a limitation to their process; also, both dyeing curves take 130 minutes, to which you have to add pre-scouring time plus after-scouring time. Besides, all their experiments are runned with a single dyestuff leading one to wonder what the results would be if 2 or 3 dyestuff combination formulas are used. Again, all tests were performed using a very high 20:1 liquor to goods ratio.
U.S. Pat. No. 4,515,596 to Berendt, Hans-Ulrich; Pacher, Marielise (May 7, 1985)
According to Berendt et al, on The Prior Art U.S. Pat. No. 4,515,596 the scour/bleach operation is performed simultaneously in the after-scouring step, thus dyeing is done on the grey materials, in such a way that the scouring time is saved, but among the many problems we encounter with this process are: (a) only works with a limited combination of fiber reactive dyes; (b) works only with light shades and one dye color formulations as demonstrated on all the examples given; (c) the exhaustion dyeings were all performed using a 40:1 liquor ratio which is highly uneconomical considering that 20% hydrogen peroxide has to be used for bleaching; (d) does not favor the environment; and (e) natural fibers vary in dyeability depending not only on their kind and locality but also on their chemical pretreatment such as scouring and bleaching, it is therefor necessary to establish the proper scouring conditions for the dyeing steps to be able to get good reproducibility and uniform dyeings.
The American Cotton Handbook, volume two, page 760 states that the amount of water needed to process one pound of cotton will run anywhere from forty to seventy gallons, while with this novel process of the present invention the amount of water needed will be about 6 to 7 gallons per pound of cotton processed, that is to say only about 10% of the water required according to the American Cotton Handbook.
In general, the five, and six bath process according to teachings of the present invention is neither taught nor suggested by the known prior art.